Drill rod



Nov. 1, 1960 flu- P. H. BENNETT 2,958,513

DRILL. Ron

Filed March 13, 1958 1NVENTOR. Paul H. Bennett WHITEHEAD, VOGL 8: LOWE PERfMm/fw- ATTORNEYS DRILL ROD Paul H. Bennett, 523 W. 14th St., Tempe, Ariz.

Filed Mar. 13, 1958, Ser. No. 721,311

4 Claims. (Cl. Z55-28) This invention relates to pneumatic rock drills and more particularly to the drill rods therefor, a primary object of the invention being to provide a novel and improved drill rod for a pneumatic rock drill.

Another object of the invention is to provide an improved drill rod for a pneumatic rock drill which incorporates comparatively simple modifications to a conventional drill rod and without modifications to the connection with conventional drills and hammers.

Another lobject of the invention is to provide a novel and improved arrangement of pulverizing heads at the base of a pneumatic rock drill which are adapted to pul- Verize stray rock particles in a drill hole as the drill is being withdrawn therefrom and avoid the common occurrence of the drill lWedging in the hole during withdrawal.

Another object of the invention is to provide a novel and improved drill rod for a pneumatic rock drill which is adapted to cooperate with the bit in scavenging cutting dust and particles from a hole being drilled, including larger pieces of rock which may nd their way into the hole above the bit during the drilling operation and which normally remain in the hole and tend to wedge a drill into the hole, especially when it is being withdrawn therefrom.

Another object of the invention is to provide a novel and improved iluted arrangement of pulverizer heads on a conventional drill rod which are adapted to crush and pulverize rock particles that may find their way into a hole being drilled, and thereby prevent such rock particles from reaching and wedging the drill bit in the hole.

Still other objects of the invention are to provide an improved uted arrangement of pulverizer heads in an improved drill rod for a pneumatic rock drill that cooperate with the drill to facilitate scavenging a drill hole, which are simple in form, neat in appearance, easily formed on a conventional rod, and comprise a rugged and durable improvement thereto.

With the `foregoing and other objects in view, all of which more fully hereinafter appear, my invention comprises certain novel and improved constructions, combinations and arrangements of parts and elements, as hereinafter described and as defined in the appended claims and illustrated in preferred embodiment in the accompanying drawing, in which:

Figure l is an elevational view of a fragmentary portion of a drill rod showing the end of the rod modified to incorporate the present invention therein.

Figure 2 is a sectional plan View of the rod as taken from the indicated line 2-2 at Fig. l.

Figure 3 is a bottom view of the rod as from the indicated arrow 3 at Fig. l.

Figure 4 is an elevational view of the rod similar to Fig. l, but illustrating the rod as having a bit attached thereto and being in a drill hole and illustrating how stray rock particles within the hole are crushed when drilling is in progress.

Figure 5 is a sectional plan view as taken vfrom the indicated line 5-5 at Fig. 4.

Typical of American industry, equipment for pneumatic rock drilling has become completely standardized. Although many variations of bits, drill rods and reamers have been proposed, it has been found that practically all of the proposed improvements cannot be put to use because it is not practical from an economic viewpoint to incorporate such proposed improvements into the standardized elements which constitute ordinary rock drill equipment.

Pneumatic rock drilling is at best a rugged operation which places excessive strain upon the equipment, necessitating frequent replacement of rods and drill bits. To meet such service requirements with maximum economy, it is essential that the component elements be kept as simple as possible and comprise only the drill, the rod extending therefrom, and the drill bit aixed to the end of the rod, all of Which have been standardized to a rugged simple form to meet the severe operating conditions.

ln working with this conventional drilling equipment, certain disadvantages and operational problems have been encountered. Perhaps the most serious problem involves the accidental occurrence of rock particles in the drill hole above the drill during the drilling operation, for such particles may easily accumulate and wedge a drill into the hole to prevent its turning, or, what is more common, to prevent it from being withdrawn from the hole. Moreover, such particles cannot be easily removed from the drill hole.

The circulating scavenging fluid, either air or Water, is adapted to pick up the dust and drill cuttings, and to move the same to the top of the hole, but the fluid velocity is usually insufficient to lift and carry larger particles of rock. lt follows that there is a real and definite need to meet the problems imposed by stray rock particles which may nd their way into the drill hole. Reaming devices have been proposed for this purpose in the past, but they have been found to be unsatisfactory because they complicate the equipment used for drilling and restrict the passageways at the reaming areas in such a manner that the scavenging fluid velocity is increased to get past the pulverizer flutes, to the point where stray rocks and particles merely lie in the drill hole above the reamers.

With such in view, the present invention was conceived and developed and comprises, in essence a plurality of tapered pulverizer heads at the base of the drill rod in a iiuted arrangement having diverging flute-ways which function to crush rock pieces in the drill hole to particles sufficiently small as to permit the scavenging fluid to carry them out of the hole and thereby produce a clean hole free of such particles which may wedge the drill, either during a drilling operation or when it is being removed from the hole.

Referring more particularly to the drawing, the irnprovement is to modify the base end of a drill rod 10 which is of a conventional type. This type of rod is usually hexagonal in section with longitudinally extended flats 11 and corners 12 characteristic of the hexagonal shape, and the rod also includes an axially centered passageway 13 throughout its length for passage of the scavenging fluid therethrough. The upper end of this rod is attached to a pneumatic drill in a conventional manner which need not be discussed herein. The lower or base end of the rod which is ordinarily upset to increase the diameter somewhat, is also upset to form the improvement, hereinafter described. This lower end conventionally includes an axially centered threaded stub 14 extending from the base end 0f the rod yand a transversely flat peripheral shoulder 15 at and defining said base end. The conventional drill bit 16 is formed as a short cylindrical body and a llat peripheral rim 1.7 at the top of a threaded cavity, not shown, which is adapted to receive the stub 14 with the rim 17 labutting against the shoulder 15 of the drill rod when in position. In the usual construction, four short heads 18 depend from this body 16 of the bit to terminate as cutting edges 19 in the form of a cross characteristic of this type of bit.

The improved base of the rod is enlarged somewhat by upsetting, as is conventionally done butthe pattern of the upsetting dies is modified to encompass the invention. Each bottom corner 13 of the hexagonally-faced drill rod is headed outwardly at the shoulder 15 and a short distance thereabove, with the heads 20 taking on the general shape of a half-cone outstanding from the wall of the rod, each half-cone head 20 having its apex 21 fairing into a corner edge 13 a short distance above tbe shoulder 15 surface and its base 22 at the shoulder 15. Each half-cone head 20 diverges outwardly from each side from its apex 21 to extend into the adjacent flats 12 as it expands in size to the base 22 at the shoulder 15 of the rod. The form of the half-cone is merged into the flats 12 by suitable fillets 23 and the arrangement forms diverging passageway flutes between the heads 26.

It follows that the base 22 of each head 20 enlarges the diameter of the drill rod at the shoulder 15 to approach the diameter of the bit, so that the extended edges of the base corners will almost, but not quite, lill the hole being drilled by the bit.

In operation, the heads 20 restrict the passageway about the bit so that the velocity of scavenging iluid moving upwardly through the hole is increased at the flute spaces between each head. Whenever a stray piece of rock drops into the drill hole it will fall downwardly against movement of the scavenging fluid to the point where the heads are located, but the increased fluid velocity at the passageways between each head, and especially at the base edge 22 of the heads will prevent the dropped particles from reaching the bit. Because of their tapered construction, the flutes will receive the particles, indicated as P at Fig. 4, and then the heads 20 will move against and crush them against the wall of the hole incidental to rotation of the bit during drilling. Moreover the bit rotation will continue to crush and pulverize the rock particles P to a point where the scavenging fluid will take over `and lift them upwardly and out of the hole. It follows that with the operation of a drill having such heads 20, stray rock particles will be easily scavenged from the hole and will not ordinarily reach the bit. The commonly occurring jamming and wedging of the bit because of stray rock particles above the bit is thereby practically eliminated.

Moreover, the common jamming and wedging of the drill when it is being withdrawn from a hole is practically eliminated in the usual drilling operation. The drill rod remains connected with the drilling machine as it is ybeing withdrawn from the hole and will rotateV continuously during the withdrawal. With the improved fluted arrangement of tapered heads herein described, this rotation Will crush all -rock particles during such withdrawal and avoid the jamming and wedging of the drill in the hole which is a common occurrence with conventional, smooth-shouldered drill rods.

To the obvious operational advantages of this drill rod improvement, there is also the practical advantage of being able to form the same in aY simple, upsetting operation that is no different than that ordinarily done when the drill rod stub and shoulder is being formed in a shop, for this improved construction may be accomplished with only simple modification of the upsetting dies used in the conventional forming of the end of the drill rod by incorporating in the dies the tapered head forms.

While l have now described my invention in considerable detail, it is obvious that others skilled in the art may devise alternate and equivalent constructions which are within the scope and spirit of my invention. Hence, l desire that my protection be limited not to the constructions herein illustrated and described, butonly by the proper scope of the appended claims. Y

l claim:

l. ln a drill rod for a rotatable rock drill having a bit-abutting base shoulder and threaded stub at its shoulder adapted to hold a bit, a plurality of conically-tapered heads arranged about the rod at the shoulder thereof to 'outstand from the rod in a substantially regular divergingly-iluted array with the cone-axis of each head being aligned substantially parallel with the axis of the drill rod and being substantially at the surface of the drill rod, with each head being of maximum size at the shoulder and fairing into the surface of the rod a short distance thereabove.

2. ln the organization deiined in claim .1, iillets between the surface of each head and the wall of the drill rod.

3. In the `organization dened in claim 1, said drill rod being formed in section as a regular polygon having a plurality of ats and corners thereon with said heads being located at each corner, with the cone axis of each head being substantially at a corner.

yLl. ln the organization dened in claim l, said drill rod being formed in section as a regular polygon having a plurality of ilats and corners thereon with said heads being located at each corner, with the cone axis of each head being substantially at a corner and fillets between the surfaces of each head and the wall of the drill rod.

References Cited in the file of this patent UNlTED STATES PATENTS Re. 16,061 Thurston May 5, 1925 2,579,720 Atkinson Dec. 25, 1951 2,739,791 Dimitrieff Mar. 27, 1956 

